How did life on Earth originate? Did replication or metabolism come first in the history of life? In this updated and expanded second edition of Origins of Life, Freeman Dyson examines these questions and discusses the two main theories that try to explain how naturally occurring chemicals could organize themselves into living creatures. Dyson analyzes the debate with reference to recent important discoveries by geologists and chemists. His main aim is to stimulate new experiments that could help to decide which theory is correct. This clearly-written, fascinating book will appeal to anyone interested in the origins of life.